I don't normally reveal this much about my personal life on the internet but, for some context to my opinion, here goes...
I spent from 4 to much as 12 weeks a year traveling around a fairly large portion of western North America from Prince George in the north to central Baja California in the south all in some sort of 4X almost every year for two plus decades starting in the late 1970s. I did it mainly in one of three different vehicles: a four door SUV (79 FJ55), a light duty pick up (GM single cab 3/4T 4X4 w/ topper), and smallish 4 wheel drive station wagon (AMC Eagle). Where accessible I have seen the Pacific shore for most of that length and travelled inland as far as 1000 miles in places. I am less familiar by far with the deserts of the southwestern US than I am with the Rockies and Sierras and North Cascades but, truthfully, I can't begin to remember where all I've been and what I saw and didn't. The world was a big place then, with surprise and wonder around every corner. There were no cell phones. There was no internet. No Google Maps. Sadly, perhaps, the Earth has only grown smaller and become largely homogenous now, with every rock and vista pre-scouted and the subject of it's own badly over-produced hyper-biography available to watch anywhere, anytime, including while driving to see it. In urban centers a single brush has now painted most of the West, both large and small, with a mundane, repetitive commercial/industrial slurry. They call it "Sprawl".
One can still get away and experience true wonder if you have the right mind set but, back in those years, you were, by default, on your own and weeks might pass without anyone knowing your whereabouts. The sense of perspective was crushing and exalted all at the same time. Because of my absences I owe apologies to many for provoking their concern and furrowing their brows. I never had a phone, a plan, or "bucket list". I almost never had a camera. My aim was to travel and camp and explore and, occasionally, have a night out in a big city until either the money or my wanderlust ran dry. Whatever came was alright by me. There was no win or lose - no success or failure - with travel like that. All was good. I ventured where I wanted and when I wanted. I swam in rivers to bathe and ate my simple fare often alone and under the stars. I woke to the sun as well as to new-fallen snow. I took lodging when needed or desired. I did this with partners and without. I humbly offer these few thoughts...
With what you describe - i.e. - living arrangements for 2, occasional transportation for 4 (or more), some load carrying capacity for somewhat minimized gear requirements, the ability to get around in large urban areas without difficulty or attracting too much attention when pursuing entertainment/restocking/hotel camping/guerrilla squatting, coupled with the need to cover ground both on-highway and off, and no specific time frame within which to complete an itinerary because next year you can pick up wherever you left off last year - I would suggest a largish SUV or a mid-sized extra cab PU (w/folding second row seats) combined with a large topper or even a spartan pop-up camper. Forego any extraneous bling or battery (By that I mean "armament" that you will battle the elements with). Include a mid-sized tent for nice weather and secure locations. Sleep inside in inclement weather or in a parking lot/rest stop if needed. Neat and discreet. Plus what's under the hood can be oh so sweet without anyone being the wiser.
You say you're envisioning this as a yearly activity for a long time to come so what's the rush to nail down your ultimate vehicle? In two or three years, as you settle into your own rhythm, you can easily sell off and build a more dedicated rig tailored to suit.
I've almost certainly said more than enough but I can elaborate if you'd like.